This invention relates generally to trim panels with electrical wiring incorporated therein and, more particularly, to trim panels which make use of flat wiring.
U.S. Pat. No. 4,904,429 recites a method of producing an instrument panel of a motor vehicle or similar molding of foamed resin capable of fitting electrical parts thereon as desired. More particularly, the ""429 Patent recites a method of producing a molding of foamed resin in which a flexible printed circuit (FPC), which is electrically connectable to electrical parts, is buried.
The ""429 Patent also recites that an instrument panel has customarily been implemented as a laminate having three layers, i.e., a covering made of soft resin, a base made of ABS resin or similar hard resin, and a padding made of foamed urethane or similar foaming resin and sandwiched between the covering and the base, and that an FPC and couplers are each mounted on the base by using adhesive or screws. Continuing, the ""429 Patent recites that such a prior art three-layer instrument panel, however, is not satisfactory because the base and the padding have to be produced independently of each other and then bonded together, resulting in a disproportionate production cost.
As an alternative to the prior art three-layer instrument panel described by the ""429 Patent, the ""429 Patent recites that the base may be formed from a foamed resin and molded integrally with the padding. However, when the base is formed from a foamed resin, the ""429 Patent then discloses that the FPC and couplers may not be mounted with screws or adhesives. Consequently, the ""429 Patent proposes. a solution for mounting the FPC and couplers to this alternative structure by burying the FPC and couplers in the base when the latter is molded.
In light of the ""429 Patent, what is needed is a structure and method of combining a flat wire with a three-layer interior trim panel without the need for separate fasteners, such as screws, or adhesives.
Accordingly, the present invention provides a structure and a method for combining a flat wire with a three-layer instrument panel without the need for separate fasteners, such as screws, or adhesives.
According to one feature of the invention, a vehicle interior trim panel is provided comprising a skin, a substrate, a foam located between the skin and the substrate, and a flat wire at least partially surrounded by and embedded in the foam. The wire herein is therefore either physically placed within the foam, or, in the alternative, chemically bonded to the foam material.
According to another feature of the invention the flat wire comprises a flexible printed circuit.
According to another feature of the invention, the foam comprises a density between 0.016 g/cm3 to 0.288 g/cm3.
According to another feature of the invention, the foam comprises an ultimate elongation greater than five percent.
According to another feature of the invention, a vehicle interior trim panel is provided comprising a skin, a substrate, a foam located between the skin and the substrate, and a switch at least partially surrounded by and embedded in the foam.
According to another feature of the invention, a method of forming a vehicle interior trim panel comprises providing a substrate, a skin, a flat wire between the substrate and skin, and forming a foam layer between the substrate and the skin surface such where the foam bonds the substrate to the skin and at least partially surrounds and embeds the flat wire in the foam layer.
According to another feature of the invention, the step of forming the foam layer further comprises molding the foam layer below twenty-five pounds-per-square-inch molding pressure.